Jupiter Ace

Hrm, hrm:

OK, you're right! In some countries it is illegal to re-engineer, but this
cute home computer is really outdated - if it ever had a big time it had
been in the early eighties.

Accidentally I got access to one of this rare machines. So I took some
time to dive into its secrets. The results are a listing and a schematic
in this small corner of home computer history. If you have some fun with
it, I'm pleased. Because I had a lot of support by the
ZX-Team, I wrote an article for the
magazine. This text you'll find archived, however, it is german. Feel free to
translate it!

Strange enough, a nice Spaniard named Isidro found it interesting to
build an Ace himself. And even more strange, it is working! Please
look below for pictures and more... A big Thank-You goes
to him for reporting the "Last Bug"!

Download:

jupiter.zip Archive with listing, german
text, and OrCAD schematics, 173KB.

Schematics:

This is my schematic, with Isidro's corrections. (68KB)

And this is the schematic of Isidro's selfmade Ace, he's using newer
memory chips and a voltage regulator. (56KB)

If you click the pictures, you'll get the packed PDF files. It can be zoomed
to get the labels and texts readable.

If you like to go further:

The operating system

The listing was made by disassembling and staring firmly on the code.
Every now and then I ran the assembler to be sure not to make any errors,
and so you can rely on it. Unfortunately I don't know of any source of a
manual in the web. Just put your hands on a good book of Forth and
start experimenting.